poly(4,4’-methylenebis(phenylisocyanate)-alt-1,4;MDI/ polytetramethylene glycol/ 1,4-butanediol copolymer;1,4-BUTANEDIOL-METHYLENEBIS(4-PHENYLISOCYANATE)-POLY(TETRA.;Diphenylmethane-4,4’-diisocyanate,1,4-butanediol,polytetramethyleneglycolpolymer;1,4-Butanediol,p,p-diphenylmethanediisocyanate,polytetramethyletherglycolpolymer;POLY[4,4'-METHYLENEBIS(PHENYL ISOCYANATE)-ALT-1,4-BUTANEDIOL/ POLYTETRAHYDROFURAN];Poly(tetramethyleneether)glycol,1,4butanediol,4,4’diphenylmethanediisocyanatepolyurethane;1,4-Butanediol, polymer with α-hydro-ω-hydroxypoly( oxy-1,4-butanediyl) and 1,1'-methylenebis[4-isocyanatobenzene];1,4-Butanediol,polymerwith.alpha.-hydro-.omega.-hydroxypoly(oxy-1,4-butanediyl)and1,1’-methylenebis(4-isocyanatobenzene);1,4-Butanediol, polymer with .alpha.-hydro-.omega.-hydroxypoly(oxy-1,4-butanediyl) and 1,1-methylenebis4-isocyanatobenzene